For the last recipe in this chapter, we will look at the popular crontab utility, a service that will execute a command or script at a regular interval of your choosing. It is a vital part of the system administrator's toolbox, and one you'll find a lot of uses for, especially when connecting to sensors and Internet of Things devices.
If you followed the recipe to make the Raspberry Pi Zero temperature script, you are ready to go.
Let's start logging the temperature of the Zero to a text file. We will take a reading every minute and save it in the /var/log/rpz_temp.log file. Over the course of a day, especially on days when you are using the Pi a lot, or it is warmer or cooler where your Pi is located, you should see changes in temperature. The crontab utility is built into pretty much every Linux system, and you don't have to worry about installation for Raspbian. Generally, if you are working...